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This is really excellent stuff that I hadn't seen before - seems like every few years when I look into this subject more and more information is availible. I'll pull out my ECU and take some pictures to post here.

I would like to swap over to EJ25D heads and manifold as I have tons of those components - I also have a TD05-16G and a Forester XT intercooler - I should be able to use most of the EJ22T components on the 25D manifold but the injectors will definitely change and of course there would be little point to all that work if there wasn't a bigger turbo and more boost pressure to be had as well. All that requires tuning that has, in the past, required a standalone to do properly. It just seems like such a waste when the stock ECU could handle what I need with just a few tweaks to it's ROM.

This is really excellent stuff that I hadn't seen before - seems like every few years when I look into this subject more and more information is availible. I'll pull out my ECU and take some pictures to post here.

I would like to swap over to EJ25D heads and manifold as I have tons of those components - I also have a TD05-16G and a Forester XT intercooler - I should be able to use most of the EJ22T components on the 25D manifold but the injectors will definitely change and of course there would be little point to all that work if there wasn't a bigger turbo and more boost pressure to be had as well. All that requires tuning that has, in the past, required a standalone to do properly. It just seems like such a waste when the stock ECU could handle what I need with just a few tweaks to it's ROM.

GD

Actually, this has been done from what I am told. a couple guys local have done this even. One of them recently went with a bigger turbo and supporting mods, so he went with a stand alone, but the others made modifications to the ECU with some chip available from a guy on one of the forums.

Actually, this has been done from what I am told. a couple guys local have done this even. One of them recently went with a bigger turbo and supporting mods, so he went with a stand alone, but the others made modifications to the ECU with some chip available from a guy on one of the forums.

I don't want a chip with someone's propietary code on it - I want to be able to modify the parameters myself as well as log the real time data streams.

Actually, this has been done from what I am told. a couple guys local have done this even. One of them recently went with a bigger turbo and supporting mods, so he went with a stand alone, but the others made modifications to the ECU with some chip available from a guy on one of the forums.

I believe that's the "robtune" available for the OBD1 EJ20G. It's a few hundred for a chip that's locked down. I looked into this for my EJ20G, but I decided I'd rather like to understand what's going on and be able to tune it at my leisure. The EJ22T ECU is different from what I read.

This, the thing to do these days is use an ej20g ecu for your ej22t and there is a guy that will tune it for you, look on legacy central, search for "robtune".

Yup and he's local to me (Puyallup). Maybe later this year or the beginning of next year I'll be getting a chipped EJ22T ECU from him. I could care less about me messing with the parameters of this ECU, if I want to do that (down the road) I'll get the EJ20G ECU. Theres a good write up LC about making the EJ20G ECU work for a franken engine.

Again - that's all well and good if all you want is an off-the-shelf tune on a chip and you don't care about ever changing anything or tinkering. Personally I like to play with things - and the 22T ECU is perfectly cabable of doing what needs to be done - not to mention it's a lot more accesible - easier to source replacements. There are a lot of folks that would like to not have to source a 20G ECU and not have to mess with their wiring, and not have to rely on someone who sells tuner chips.

Again - that's all well and good if all you want is an off-the-shelf tune on a chip and you don't care about ever changing anything or tinkering. Personally I like to play with things - and the 22T ECU is perfectly cabable of doing what needs to be done - not to mention it's a lot more accesible - easier to source replacements. There are a lot of folks that would like to not have to source a 20G ECU and not have to mess with their wiring, and not have to rely on someone who sells tuner chips.

GD

This runs completely counter to all the accumulated wisdom on Legacy Central.

The ej22t ecu is very limited in it's capabilities.

Standalone or ej20g ecu are the de-facto options according to everyone who has years of experience messing with these things.

GD, do you know of a secret stash of 22T ECU's? Cause they are getting as rare as the engines now. If you use a EJ20 ECU (OBDII) its tuning capabilities are tons more accessible and tuneable than any 22T ECU would ever be. And if you use a access port with it you could run any number of maps.

boy the buggy could use some ecu help higher redline and more feul and more feul and more feul lol anyway can you change the injector pulse width ? i tryed some injectors that were to big whould like to use them and slow down the pulse width so can get more feul to the engine a'm running a 550 whould like to run the 800s i have but is just to mutch for stock ecu

GD, do you know of a secret stash of 22T ECU's? Cause they are getting as rare as the engines now.

They seem to be laying around junk yard shelves all over the nation based on car-part.com. There's also the legacycentral bbs. They can be found and they have a very low failure rate.

OBD-I vs. II is not really that helpful from a tuning perspective - once you have control over the maps and RTD streams there aren't any real differences - it's really just a communications protocal preference. There is nothing wrong with the SSM interface.

This runs completely counter to all the accumulated wisdom on Legacy Central.

The ej22t ecu is very limited in it's capabilities.

Limited in what way?

The tuning limitation is what this thread is talking about overcoming.

If the EJ20G ECU can run the 22T so easily it's because they have essentially the same hardware minus the 4 channel ignition. That means that any "limitations" are software based and that's the whole point of hacking the code - to overcome the software limitations. When/if we have complete software control of the stock ECU it BECOMES a standalone with most of the same features and abilities.

Besides all that - I don't really care what other people want to do or what they want to use. I'm more interested in the process of reverse engineering the code on an ECU.... any ECU really.... as a learning experience. This just happens to be the one I own and daily drive so it's accesible to me and I don't have to pointlessly rewire my car. I'm a former full-time software engineer and I enjoy the experience and challenge.

i have bins of ecus but all time favorte is the 89-90 legacy na standard trans ecu dumb as a post just feul and spark non of that diagnostic or limp home crap i find it works realy good in turbo app i can put in ad ons and ecu dosent know

I know this is an older post, but it made me wonder.. With the tablets available today and being as cheap as they are, wouldnt it be easier to copy the data from the ECU to a tablet where you would be able to modify data on the fly?

I dont really see the point in using a serial data port anymore, when there is a lot new and improved ways of communicating to the engine/trans.

It'd almost be like the banks power programmer (the palm pilot one) on a diesel. You have your normal driving fuel maps, rally fuel maps, dump raw fuel on the ground fuel maps etc.

Something to answer one of the initial questions, maybe, regarding a socket in the EJ22T ECU. This is/was the ill-fated Revtronix chip that I was one of the initial buyers/guinea pigs for - w/a TD04 and 440cc's I made 50% more power:The cable allowed 2 modes that could be switched. IIRC, recommended to turn of the car to switch modes- Power 16.5 psi and Normal 14 psi.

Mike, the creator of the chip, had to carry an EEPROM (?) programmer w/him to recalibrate the chip: pull it, change the settings, replace, test. He was supposedly working on a tunable chip, but he disappeared over 2 years ago....never heard from him again. There's more info on Legacy Central.

There is the Revscan software avl (I have a copy somewhere) that allowed datalogging AND w/the chip installed, the fuel tables could be modified and Codes reset via a cable connected to the SSM. I 'think' the Revscan worked on the un-chipped ECU, too??? But can't recall.

I do NOT understand the software-side of this (although I'm supposedly an 'IT Professional') and tuning my Forester project w/a Greddy EMU did not go well.

For Torxxx, the SSM interface on the older Legacy (pre-OBD2 connector) is a limiting factor, and using a USB-Serial adapter or straight Serial may be the only viable to way to 'get in'.

FWIW, I also ran the Rob Tuned EJ20G ECU on the same car - more info HERE, if you're bored.Td